import {asyncRoutes, constantRoutes} from '@/router'
import {getMenuTree} from '@/api/menu'
import Layout from '@/layout'

/**
 * Use meta.role to determine if the current user has permission
 * @param roles
 * @param route
 */
function hasPermission(roles, route) {
    if (route.meta && route.meta.roles) {
        return roles.some(role => route.meta.roles.includes(role))
    } else {
        return true
    }
}

/**
 * 后台查询的菜单数据拼装成路由格式的数据
 * @param routes
 */
export function generaMenu(routes, data) {
    data.forEach(item => {
        //alert(JSON.stringify(item))
        let url = item.component;
        const menu = {
            path: item.path === '#' ? item.id + '_key' : item.path,
            //webpack4中动态import不支持变量方式，使用require([`@/views/${view}`], resolve)
            component: item.component === 'Layout' ? Layout : (resolve) => require([`@/views/${url}`], resolve),
            // hidden: true,
            children: [],
            name: 'menu_' + item.id,
            meta: {title: item.label, icon: item.icon, id: item.id, roles: ['admin']}
        }
        if (item.children) {
            generaMenu(menu.children, item.children)
        }
        routes.push(menu)
    })
}

/**
 * Filter asynchronous routing tables by recursion
 * @param routes asyncRoutes
 * @param roles
 */
export function filterAsyncRoutes(routes, roles) {
    const res = []

    routes.forEach(route => {
        const tmp = {...route}
        if (hasPermission(roles, tmp)) {
            if (tmp.children) {
                tmp.children = filterAsyncRoutes(tmp.children, roles)
            }
            res.push(tmp)
        }
    })

    return res
}

const state = {
    routes: [],
    addRoutes: []
}

const mutations = {
    SET_ROUTES: (state, routes) => {
        state.addRoutes = routes
        state.routes = constantRoutes.concat(routes)
    }
}

const actions = {
    generateRoutes({commit}, roles) {
        return new Promise(resolve => {
            const loadMenuData = []
            // 先查询后台并返回左侧菜单数据并把数据添加到路由
            getMenuTree(state.token).then(response => {
                let data = response
                if (response.code !== 0) {
                    this.$message({
                        message: '菜单数据加载异常',
                        type: 0
                    })
                } else {
                    data = response.data
                    Object.assign(loadMenuData, data)
                    generaMenu(asyncRoutes, loadMenuData)
                    let accessedRoutes
                    if (roles.includes('admin')) {
                        // alert(JSON.stringify(asyncRoutes))
                        accessedRoutes = asyncRoutes || []
                    } else {
                        accessedRoutes = filterAsyncRoutes(asyncRoutes, roles)
                    }
                    commit('SET_ROUTES', accessedRoutes)
                    resolve(accessedRoutes)
                }
                // generaMenu(asyncRoutes, data)
            }).catch(error => {
                console.log(error)
            })
        })
    }
}

export default {
    namespaced: true,
    state,
    mutations,
    // actions
}
